(i) Technical Field
This invention relates to an image formation apparatus of a printer, a copier, a facsimile, etc.
(ii) Related Art
In this kind of image formation apparatus, a charging device for applying a bias voltage having an AC voltage superposed on a DC voltage is widely used for giving uniform charging to a photoconductor. It is known that if the AC voltage in the bias voltage is lowered to a value at which the photoconductor surface potential becomes the saturation point or less, an image defect (image lack, color change, etc.,) is caused by uneven charging of the photoconductor and the quality in an output image is degraded.